• Title/Summary/Keyword: dent imperfection

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Buckling assessment of dented truncated cones under external pressure

  • Ghazijahani, Tohid Ghanbari;Showkati, Hossein;Jiao, Hui
    • Advances in Computational Design
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    • v.1 no.4
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    • pp.345-356
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    • 2016
  • Notwithstanding a considerable body of references in the literature on the buckling response of conical shell structures, it seems imperative to provide further insight on the buckling response of locally imperfect steel cones. This paper contains different simulations including non-linear FE analysis and discusses the influence of dent imperfection on the buckling load of these structures subject to external pressure. Data of the present work are evaluated against available experimental results, codes and recommendations and the effect of the local damages is exhaustively set forth. It is also found that the employed FE program can reliably predict the structural response of locally damaged conical shells.

Experiments on locally dented conical shells under axial compression

  • Ghazijahani, Tohid Ghanbari;Jiao, Hui;Holloway, Damien
    • Steel and Composite Structures
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    • v.19 no.6
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    • pp.1355-1367
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    • 2015
  • Steel conical shells have long been used in various parts of different structures. Sensitivity to the initial geometrical imperfection has been one of the most significant issues on the stability of these structures, which has made them highly vulnerable to the buckling. Most attention has been devoted to structures under normal fabrication related imperfections. Notwithstanding, the challenges of large local imperfections - presented herein as dent-shaped imperfections - have not been a focus yet for these structures. This study aims to provide experimental data on the effect of such imperfections on the buckling capacity of these shells under axial compression. The results show changes in the buckling mode and the capacity for such damaged thin specimens as is outlined in this paper, with an average overall capacity reduction of 11%.

Fatigue tests of damaged tubes under flexural loading

  • Ghazijahani, Tohid Ghanbari;Jiao, Hui;Holloway, Damien
    • Steel and Composite Structures
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    • v.19 no.1
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    • pp.223-236
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    • 2015
  • Despite the proliferation of the industrial application of steel tubes, the effect of collision on the surface of steel tubes subject to cyclic loading has largely remained untouched. This paper studies the fatigue behavior of steel tubes which are impacted by an external object. A dent imperfection caused by a collision was modeled and fatigue tests were conducted using a MTS machine. Fatigue life as well as the failure modes were thoroughly discussed in a way that the fatigue life of the dented tubes with similar geometrical specifications at full-scale can be generalized.